<template>
  <div class="app">
    <h2>我是App组件</h2>
    <Hello/>
    <h3 v-haokan-big="n"></h3>
  </div>
</template>

<script>
  export default {
    name:'App',
    data() {
      return {
        n:1
      }
    },
  }
</script>

<style>
  .app {
    background-color: gray;
    padding: 20px;
  }
</style>